[Validator] Moved constraints Optional and Required to the Constraints\ namespace
[Form] Renamed option "virtual" to "inherit_data"
[Form] Moved parent data inheritance from data mappers to Form
[Form] Fixed the deprecation notes for the "virtual" option
Moved TypeTestCase to it's own namespace
Moved FormIntegrationTestCase and FormPerformanceTestCase to the Test namespace
Update composer.json

symfony/debug was not mentioned in the replace list
merged branch sstok/patch-6 (PR #7723)

This PR was merged into the master branch.

Discussion
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Update composer.json (symfony/debug was not mentioned in the replace list)

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

symfony/debug was not mentioned in the replace list

Commits
-------

57d476b Update composer.json
merged branch WouterJ/form_test_namespace (PR #7659)

This PR was merged into the master branch.

Discussion
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[Form] Moved TypeTestCase to the Test namespace

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #7175
| License       | MIT
| Doc PR        | symfony/symfony-docs#2500

Todo:
 - [x] Make a Doc PR
 - [x] Update the changelog and UPGRADE-3.md files

As discussed in #7175, since this class is documented as a practise to test your form types, it's good to move it to the `Test` namespace.

I am not sure about the deprecation, I thought things deprecated in 2.3 are removed in 3.0. Also, I think we shouldn't trigger a E_USER_DEPRECATED message.
Please correct me if I'm wrong, it's my first PR for the core code.

Commits
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8da6129 Moved FormIntegrationTestCase and FormPerformanceTestCase to the Test namespace
e46f841 Moved TypeTestCase to it's own namespace
merged branch bschussek/move-existence-constraints (PR #7701)

This PR was merged into the master branch.

Discussion
----------

[Validator] Moved constraints Optional and Required to the Constraints\ namespace

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | symfony/symfony-docs#2512

Commits
-------

a868048 [Validator] Moved constraints Optional and Required to the Constraints\ namespace
merged branch bschussek/issue5899 (PR #6573)

This PR was merged into the master branch.

Discussion
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[2.3] [Form] Renamed option "virtual" to "inherit_data" and improved handling of such forms

Bug fix: yes
Feature addition: yes
Backwards compatibility break: yes
Symfony2 tests pass: yes
Fixes the following tickets: #5899, #5720, #5578
Todo: -
License of the code: MIT
Documentation PR: symfony/symfony-docs#2107

This PR renames the option "virtual" to "inherit_data" for more clarity (the old option is deprecated and usable until 2.3). It also fixes the behavior of forms having that option set.

Forms with that option set will now correctly return their parents' data from `getData()`, `getNormData()` and `getViewData()`. Furthermore, `getPropertyPath()` was fixed for forms that inherit their parent data.

Commits
-------

1290b80 [Form] Fixed the deprecation notes for the "virtual" option
ac2ca44 [Form] Moved parent data inheritance from data mappers to Form
8ea5e1a [Form] Renamed option "virtual" to "inherit_data"